1. Field of the Invention
The present invention relates to the protection of digital contents. More particularly, the present invention relates to a domain management method and device which can create and delete a domain, add a device to the domain, or delete the device from the domain, so as to protect digital contents.
2. Description of Related Art
Digital content protection is a very important issue for content owners. If there is no content protection mechanism, content owners cannot receive a profit from a distributed content since anyone can freely access and utilize the distributed content. Accordingly, content owners usually implement some mechanism that allows them to protect the content from unauthorized access and consumption. Typically, Digital Rights Management (DRM) is involved for protection of digital contents.
One method of DRM protection allows a group of devices to share content. In this instance, the group of devices is referred to as a single domain and the devices belonging to the single domain are allowed to share content. Such devices may, for example, have the same account information on a content provider server and share access to digital content. A user may access the content that is allowed for the domain using any of the devices.
Various types of payment methods may be utilized when providing access to the content that belongs to the single domain. As an example, an owner of the devices that belong to the single domain may freely access the content that is purchased by the owner, using any of the devices of the domain. Another payment method restricts a total number of accesses to the devices of the domain. In this instance, only the total number of accesses is restricted according to a payment, no matter how the user accesses the content using any of the domain devices. This type of DRM system is very convenient to both content owners and content consumers.
However, content consumers and device manufacturers may experience problems with management of the domain of devices. A first problem is that a device must have the ability to access the Internet, so as to be registered with a content provider or a digital rights issuer. Namely, according to a conventional art, since the device needs to be added to the domain by accessing a rights issuing server via a network, the device must have a network communication function. Accordingly, when manufacturing the device, device manufacturers must include a network-enabled function in the device, which imposes additional costs. Also, the user cannot register legacy devices, which have no network-enabled function, to the domain. Generally, the network-enabled function is not included in devices such as an MP3 player, a digital camera, and the like. Accordingly, such devices cannot use a domain function of DRM system according to the conventional art. Another problem is that the user has to wait a relatively long period of time to receive an authorization for the device that requests a domain membership. According to the conventional art, the authorization is usually granted by an external trusted entity, for example a rights issuer. Accordingly, it takes a very long time to establish contact with the external trusted entity. Still another problem is that all the member devices that constitute the domain must be registered when creating the domain. Accordingly, an operation of changing the member devices becomes very complicated and inflexible. Also, although all the member devices of the domain must be registered when creating the domain, it is not easy to make all the devices ready to use the content when purchasing the content. Accordingly, it is not realistic to register all the member devices to the domain, when creating the domain. Consequently, DRM methods using the domain described above are not widely utilized.
Accordingly, there is a need for an improved domain management method and device that allows a domain membership even for devices that have no ability to access a network, and that provides an easy and secure device enrollment that increases user convenience of domain management.